Originally Posted by
Lascaille
Based on the videos there should have been no difficulty picking out the lights of the CRJ, the helo is approaching it not quite head-on but definitely in the right front quadrant. And the CRJ is above all the city lights.
It is genuinely odd how they flew directly into this thing which must literally have been lighting up the interior of their cockpit. Also, why were they above the 200ft route ceiling?
(Still from the video referenced above by ORAC.)
Helo on the left
While the CRJ is clearly above the horizon from this point of view, it wouldn't have been quite so clearly above it from PAT25's point of view. Position relative to the horizon could in any case be irrelevant if both helo pilots were using NVG, because the night sky is packed with light sources which clutter the background when amplified: distant aircraft, satellites, planets and stars all compete for attention, while the saturation limit of the display prevents the actual nearest threat from being magnified in proportion.
Here's the more likely issue with NVG. Looking through them is often described as akin to looking through a pair of toilet roll tubes. Field of vision is radically reduced and it takes strong, conscious and fatiguing effort to conduct any kind of visual search.
At the start of the radar recording posted to YouTube by AvHerald, AAL3130 is 10 degrees right of the CRJ from PAT25's point of view, and at a similar elevation angle. Its landing lights would be prominent in NVG and if PAT25's pilots were fixated upon it, they would not have seen the CRJ further left unless actively moving their heads to look for it. PAT25 gradually changes heading by 2 degrees right during the course of the radar clip, almost exactly following the bearing to AAL3130, and this makes it even clearer to me that PAT25 was mistakenly holding visual on it.
